Rating System

LEED BD+C: New Construction, LEED BD+C: Schools, LEED BD+C: Retail, LEED BD+C: Healthcare

Rating System Version

v3 - LEED 2009, v2 - LEED 2.2

Inquiry

The purpose of this inquiry is to determine if our approach for energy modeling required by credits EAc1 and EAc5 is acceptable. Our project is a 215,800 square foot patient room and administration office addition to an existing hospital. The LEED boundary for the LEED certification includes the new addition only. A boiler and chiller plant provides heating and cooling to the existing hospital and is located within the existing building. The boiler and chiller plant equipment will be demolished and a new, larger boiler and chiller plant will be built within the new attached addition, and will serve both the new addition and existing hospital. The new building addition within the LEED boundary will be served by its own air handling units with hot- and chilled- water coils served from the new mechanical plant which is also within the LEED boundary. We would like to confirm that the following approaches are acceptable: 1) Exclude the existing building which is outside of the LEED boundary from the energy models; and 2) Model the new addition in the budget and proposed design models with a mechanical plant that is appropriately sized for the addition only, and use in the models the efficiencies of the plant equipment that is sized to serve the entire hospital. The equipment sized for the new addition only is in the same size category referenced in ASHRAE 90.1 Section 6 as equipment sized to serve the entire building, so the efficiencies would be the same.